1. Field of the Invention
The present invention relates generally to systems and methods for biometric identification, and more particularly, to imaging systems and methods capable of biometric identification according to more than one modality, especially for subjects positioned at a distance from the image capture system.
2. Description of the Related Art
Due to the unique character of each individual's face or iris, various systems attempt to use either the face or the iris for biometric identification. As such, commercially available imaging systems used for biometric identification generally use a single biometric modality. In other words, these systems employ imaging systems that process images of the face or the iris, but not both. As a result, these single modal systems suffer from the limitations inherent in face-only imaging systems or iris-only imaging systems. As a further disadvantage, commercially available iris-only systems usually image one iris at a time, and not two eyes simultaneously, or near simultaneously. In addition, conventional face-only or iris-only imaging systems suffer from constraints that prevent these systems from acquiring and tracking a person among multiple persons within a specified field of view from a distance. For example, the greater the distance between the imaging system and the target, the more difficult it is to acquire images that may be used for biometric identification.